i hope this helps … see attached graphic please … … what if i want to leave the ” time ” in the chord progression where the F chord is , but i want to ” not ” have any ( audio- midi ) sound occur … … so when the audio – midi is played back there is dead silence where the F chord is , ( i want something else to occur there ) in the recording … … i see how you can ” change ” the chord , but no idea how to put dead silence there , ( within the ezkeys app ) … … not having to ” edit ” the midi in the recording manually … … thank you in advance … … 
As John has suggested, I would separate the F chords within the progression using the scissor tool.
Then, by right-clicking that section of the MIDI, you can remove the F chord completely from the track leaving a gap where it was
or mute the F chord where it is. (see the right-click menu in the attachment below)
